Floor sander



May 10, 1927.

L. DURR FLOOR SANDER Filed April 16. 1923 Patented May 10, 1927.

toms-Dunner MILWAUKEE, WISCONSIN.

FLOOR SANDER.

Application filed April 1.6, 1923.- Scrial No. 632,503.

This invention relates to floor sanding machines.

Objects of this invention are to provide a floor sander which is freely portable, which is-readily adjusted to operate'upon the particular portion of the floor desired, which is adapted tobe thrown into and out ofoperation by the handle used for transporting the device, and which is adequately housed and protected against damage.

Further objects are to provide a floor sanding machine which may be very simply constructed, which is of a relatively cheap formation, and which is sturdy in design.

An embodiment of the invention is shown in the accompanying drawings, in which:

Figure 1 is a side elevation of the device with parts broken away to more clearly show the construction.

Figure 2 is a sectional view 011 the line 22 of Figure 1.

The machine comprises a main supporting casting which may consist of a platform or portion 1 adapted to support an electric motor 2 and may have an upturned angular portion 3 to further brace the sides of the machine. The sides 4 of the machine are secured to the portions 1 and 3 of the supporting casting in any suitable manner and are preferably formed of sheet iron. These side portions 4 carry a shaft 5 upon which are mounted the supporting wheels 6 for the device. Supporting wheels 7 are mounted to the rear of the wheels 6 and are carried upon stub shafts 8 secured to bell crank levers 9 whose shorter ends are pivoted, as indicated at 10, to the side plates. Their longer arms 11 are secured to an upwardly and rearwardly extending manipulating handle 12, whereby the device may be thrown into and out of operation and may be transported, as will hereinafter be described. Any suitable form of stop 13 may be provided against which arms 11 contact when the device is in position to be moved along the floor to some other place of operation.

The side frames 4 support a plurality of roller bearings 14 upon which flat drum pulleys or rollers 15, 16, 17, and 18 are revolubly mounted. A fifth pulley 19 is carried by a roller bearing 20 secured to the outer ends of levers 2]. pivoted by bolts 22 to the side frames 4 of the machine. These extensible devices, such, for instance, as the threaded rods2 3 and turn=buckles 21, so that the desired adjustment may be attained for maintaining the belt taut.

The belt-:25 is passed over the rollers15, 16, 17, 19, and 18, as indicated in Figure 1, and is preferably of the usual type of abrasive belt.- It is to be noted that the desired tension of the belt may be maintained by adjusting the turn-buckles 24c. The belt is drivenfrom thepulley 18. This pulley 18 is connected by means of a belt 26 with the pulley 27 of the motor, as may be seen from Figure 1. In order to secure the desired compactness of the device the pulley 18 is so organized that both the belts 25 and 26 may operate thereon. This is secured by forming a reduced portion 28 (see Figure 2) upon the pulley 18 and passing the belt 26 over such reduced portion, thereby avoiding the necessity of providing an auxiliary side pulley for the roller 18.

vThe operation of the apparatus is as follows :-The device is pushed into desired position by means of the handle 12. After it has been properly located and the motor started the handle 12 is swung downwardly thereby causing the shorter arms 9 of the bell crank levers carried by the handle to pivot about the point 10 and about the stub shafts 8. This elevates the rear portion of the machine and throws that portion of the belt between the pulleys l5 and 16 into contact with the floor. The degrees of pressure may be most readily controlled by the extent to which the handle is rocked downwardly. hen the desired sanding has been effected the handle is elevated thereby lifting the belt from the floor and the device may then be transported to other points.

It will be seen that a sanding machine has been provided which is of very compact formation, which is simple in construction and effective in operation.

It will further be seen that an extremely simple means has been provided for controlling the action of the sanding belt and for transporting the machine.

Although one specific form of the invention has been described in considerable detail, it is to be understood that the invention may be variously modified and is to be lim ited only as defined by the appended claims.

I claim 1. A sanding machine comprising a body portion having belt receiving pulleys, a belt passing over said pulleys and following substantially the exterior outline of said. machine, a motor carried by said frame work and driving said belt, a guiding handle hav ing a forked lower end provided with a bell crank lever pivoted to said frame work at its outer end, a pair of supporting rollers pivoted to said lever at its point of union with said handle, and a second pair of rollers pivoted to said machine at a point spaced from said handle, whereby said guiding handle functions in the capacity of a guiding handle and also as means for tilting the frame work to cause said belt to engage or move away from the floor.

2. A sanding machine comprising a body portion formed of two sheet metal members, a motor carried between said members, said sheet metal members defining roughly a triangle with a rearwardly projecting portion providing an upper cutaway portion, a

pulley carried at the apex of the triangular sheet members, a pulley carried at the forward corner of said. triangular sheet members, a pulley carried at the rear corner of the rearward extension of said sheet menr bers, a belt tightening pulley mounted in the cutaway portion of the sheet metal members, means for moving said pulley, a belt passing over each of said pulleys, means operatively connecting said motor and said belt, a handle having a forked lower end pivoted to said sheet metal members and having supporting rollers spaced from said pivot point, and a pair of rollers carried by the sheet metal members at a point spaced forwardly of said first mentioned rollers.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in, the county of Milwaukee and State of lVisconsin.

LOUIS DURR. 

